We propose to conduct the first pharmacotherapy relapse prevention study in body dysmorphic disorder (BDD). BDD, an often-delusional preoccupation with an imagined or slight defect in appearance, is a distressing, impairing, and relatively common body image disorder. It is associated with high rates of functional impairment and markedly poor quality of life. It appears that SRIs are often--and selectively-- efficacious for BDD and that many BDD patients receive SRIs. It also appears that most patients discontinue an efficacious SRI at some point, as the alternative is life-long treatment. However, no relapse prevention studies have been done. Such a study is important from a clinical and public health perspective, because BDD appears to often be chronic and require long-term treatment. It is therefore critically important to investigate the risk of relapse with SRI discontinuation, and whether continuation SRI treatment decreases relapse risk. 128 subjects will be enrolled and first treated openly for 14 weeks with escitalopram;58 escitalopram responders will then be randomized to double-blind continuation treatment with escitalopram or placebo for 6 additional months. Our primary aim is to compare time to relapse and relapse rates in responders to acute escitalopram who are then randomized to placebo versus continuation treatment with escitalopram. Secondary/exploratory aims will explore 1) Whether subjects who receive continuation escitalopram perform better on secondary outcome measures (e.g., quality of life) than those on placebo;2) Whether subjects taking continuation escitalopram have further improvement in BDD symptoms during the continuation phase;3) Predictors of relapse after escitalopram discontinuation;and 4) Acute treatment response. Because this study will offer a unique opportunity to investigate the genetic basis of BDD, we will explore BDD's genetic basis and the relationship of selected candidate genes to treatment outcome and side effects. In summary, this study will be the first relapse prevention study in BDD and the first study of continuation pharmacotherapy in BDD. It will provide critically important information on relapse with continuation versus discontinuation of an SRI, whether continuation treatment protects against relapse, and whether patients further improve with continuation treatment. It will explore previously unstudied questions about BDD's pharmacogenetics, which may ultimately guide and enhance medication treatment. This study will yield unique and clinically important data, and will fill gaps in knowledge about this relatively common, severe, and understudied illness.